This invention relates to surgical techniques in general and more specifically to the surgical techniques involved in removing skin lesions, whether for biopsy (i.e., to determine the nature of the lesion), for cosmetic reasons or for tumor removal. The general and accepted current method of skin lesion excision is to mark a pattern of excision in accordance with the type of flap repair contemplated (e.g., an ellipse for linear advancement flap repair, a V for a V-Y flap repair, etc.). The flap pattern is excised and the lesion is removed in accordance with the pattern chosen. Full-thickness skin with margins surrounding the lesion is removed. At this point, electrocautery is used to control bleeding. The edges of the excised margins are elevated to allow for some tension on these edges and then a sharp instrument (e.g., a scalpel blade or a scissors) is used to create flaps of skin on all margins of the excised wound. The margins are then undermined for some distance to allow the flaps to be advanced into a position of closure such that they do not have any tension, or have minimal tension placed upon them at the time of closure. Following this step, another session of electrocautery is used to control bleeding under the flaps. The wound margins are then approximated (i.e., closed) using suture and/or skin adhesive techniques.
Dissecting surgical tools have been used almost since the dawn of history. These tools are generally divided into tools for blunt dissection and tools for sharp/cutting dissection. As the name implies, sharp/cutting dissection involves the actual cutting of tissue; blunt dissection, on the other hand, separates along natural lines within the body by breaking the connective tissue.
The breaking of connective tissue is generally easily accomplished using a variety of tools well known in the surgical fields. Examples of tools which utilize a traditional blunt dissection are described in: “Bulbous-Lysin undermines” by Weber et al. and appearing in Dermatological Surgery and Oncology, 15:12, December 1989, page 1252; U.S. Pat. No. 4,815,465, entitled “Dissector Device”, issued to Alvarado on Mar. 28, 1989; U.S. Pat. No. 5,188,630, entitled “Christoudias: Endopongestick Probe”, issued to Christoudias on Feb. 23, 1993; U.S. Pat. No. 5,022,414, entitled “Tissue Separator Method”, issued to Muller on Jun. 11, 1991. In all of these devices, a substantially rigid member is pressed against the connective tissues to break them.
In another field of medicine, a “dissection-type” of operation is done in which balloons are used to break plaque build-up in the arterial walls. This operation, named angioplasty, uses a balloon that is inflated in the artery, thereby pressing the plaque against the artery's wall so that the bonding is broken therebetween. Examples of these devices are shown by U.S. Pat. No. 5,250,060, entitled “Angioplasty Appartus”, issued to Carbo et al. on Oct. 5, 1993; U.S. Pat. No., 4,685,458, entitled “Angioplasty Catheter and Method of Use Thereof”, issued to Leckrone on Aug. 1, 1987; U.S. Pat. No. 4,747,405, entitled “Angioplasty Catheter”, issued to Leckrone on May 31, 1988; and U.S. Pat. No. 5,219,355, entitled “Balloon Device for Implanting an Aortic Intraluminal Prosthesis for Repairing Aneurysms”, issued to Parodi et al. on Jun. 15, 1993. None of these devices, though, is a true dissector in that none breaks the connective tissue. Instead, these devices break only the plaque bonding's grip.
Some attempts have been made to use balloons in areas other than in the angioplasty field. One such example is described in U.S. Pat. No. 5,195,507, entitled “Endoscopic Surgical Instrument for Displacing Tissue or Organs”, issued to Bilweis on Mar. 23, 1993. As the title implies though, the balloon acts to merely replace or nudge the organ and no actual dissection occurs. Further, for all intents and purposes, the balloon (being made of rubber or an elastic material) is of an indeterminate size and shape, thereby limiting its application to only a few areas.
It is clear that while dissecting remains an integral part of surgery, there had not been any real development in instruments which are either tailored for specific applications, or which accomplish the actual dissecting in a gentle and controlled manner—until the advent of the following patents: U.S. Pat. No. 5,452,732, entitled “Method of Dissecting Along Connective Tissue Lines”, issued to Bircoll on Sep. 26, 1995; U.S. Pat. No. 5,549,625, entitled “Balloon Dissector”, issued to Bircoll on Aug. 27, 1996; and U.S. Pat. No. 5,725,545, entitled “Balloon Dissector”, issued to Bircoll on Mar. 10, 1998 (collectively, the “Bircoll Patents”).